Apparatus for forming sheet metal articles



\ Feb. 4,1958

D. PEccERlLL 2,821,945

APPARATUS FOR FORMING SHEET METAL =ARTICLES 2 Sheets-Sheet 1 Filed Aug, 27. 1953 ATTORNEYS Feb. 4, 1958 D. Px-:ccERlLL A2,821,945

APPARATUS FOR FORMING SHEET METAL ARTICLES Filed Aug. 27, 1953 2 Sheets-Sheet 2 INVENTOR United States Patent-"of APPARATUS FOR FORMING SHEET METAL ARTICLES Donald Peccerill, West Haven, Conn.

Application August 27, 1953, Serial No. 376,889

3 Claims. (Cl. 113-44) `This invention relates to an apparatus for shaping hollow articles, and more particularly to the shaping of articles such as containers or the like in which the inner dimensions of the article or dimensions adjacent the closed end thereof are greater than the dimensions adjacent the open end.

Many'articles such las containers or cup-shaped mem-V bers formed of sheet metal or the like are made by pressing or drawing operations, the workpiece being formed in a die cooperating with which is a punch which yenters the interior of the article to shape it and then is withdrawn therefrom.

Such a method is very readily employed where the open i end of the article or container is larger than the closed end thereof, but wherey the reverse is true it will be seen that the punch cannot form the blank or work into the desired shape and still be withdrawn from the smaller opening at the neck or open end of the work.

Various methods have been employed for forming larticles of this shape, but all have certain disadvantages in that they are not capable of continuous and high-speed operation, for various reasons. It has, for example, been According to the present invention I provide at the .lower end of the plunger a container `or bag formed of exiblernaterial which may be filled with a fluid, this bag being carried at the lower end of the plunger in such a manner that when the bag is inserted into the cup-shaped rblank or work the-plunger may travel relatively to the bag,

and thus forcethe-uid outwardly to expand the walls of the container. The parts are so arranged that the fluid is Vat all times contained within the bag andthus may be used over and over again, and for this reason. the device is capable of continued use and of relatively high-speed operation.

According to the invention, the container for the pressure fluid is not secured directly to the vplunger but is secured in fluid-tight relation upon a collar which is slid- .ably mounted upon the plunger but retained from dropping from the lower end thereof by a shoulder or other equivalent stop means. The collar is provided with means to close the upper end of the die opening so that, when the plunger is advanced into the die opening, the movement of the collar will be arrested when the bag reaches an innermost posittion, in which it will be seated within the :container .or workpiece, and ,thereafter the plunger will fbeadvanced relatively to theA collar to force the fluid out- .iwa-rdly and complete the pressing operation.

A spring is provided to normallyurge the collar, together with the bagtwhich it- .sup'poi=ts','. toward the lower entlr offtheplunger so that the latter will enter the -clie prior f I Patented Feb. 4, 1958 ICC 2 at the lower end of the plunger to maintain the bag in a somewhat extended position, so that its insertion into the work will be easily effected. Also provision is made tor filling the bag with a fluid and sealing it so that the iiuid will not escape but may be used over and over again in the present operations.

One object of the invention is to provide a new and improved apparatus for pressing hollow articles larger at their closed than at their open ends, or articles made of irregular form from which it would be diliicult or impossible to withdraw a punch made of rigid material.

A still further object of the invention is to provide an apparatus for forming hollow articles by pressure, which apparatus comprises a liquid-tight bag or container of flexible material which may be lled with a fluid, a plunger upon which the bag is carried, and means for connecting the plunger and bag such that there is relative movement between the two, so that, upon introduction of the plunger into the bag the liquid in the latter may be forced outwardly.

A still further object of the linvention is the provision of an apparatus for pressing out hollow articles by means of a plunger having at its lower end a container of flexible material, the arrangement being such that once the container is inserted into the work, the plunger will move relatively to the container within the same and thus force the flexible walls of the latter outwardly to form the work into the desired shape.

A still further object of the invention is the provision of an apparatus of the character described, wherein the fluid container will be so attached to the plunger that'it may be used over and over again without loss of the iiuid therefrom.

To these vand other ends the invention consists in the novel features and combinations of parts to be hereinafter described and claimed. l

ln the accompanying drawings:

Fig. 1 is a sectional view of an apparatus for pressing hollow articles, the apparatus comprising a cooperating die and plunger, anl the parts being shown at the beginning of a pressing operation;

Fig. 2 is a similar view of the part shown in Fig. v1, in the position occupied at the completion of a pressing operation; and

Fig. 3 is a view similar to Figs. 1 and 2, showing the parts at an intermediate position.

To illustrate a preferred embodiment of my invention, I have shown in the drawings a die 10 having therein a die opening 11 of irregular form, and it will be particularly noted that the mouth of the opening is smaller than the lower portion thereof so that an article formed therein according to the shape of the die will be larger at its lower portion than at its upper portion.

As shown, the die member 10 is divided in two sections along the dividing line 12, so that the die sections may be parted in order that the work may be withdrawn from the die. If desirable, the die member may be divided into any number of sections which may be found to be necessary to provide for the ready withdrawal of the work.

A workpiece is shown at 13, this member being illus- `trated as of cup-shaped form, although it may be formed in a preliminary way of any desired shape depending upon the shape desired in the finished article. The cupshaped member 13 may, if desired, be stamped from a disk or flat plate of sheet metal, but may be formed in any way desired. v v

As shown in the drawing, a plunger 15 is designed to cooperate withvthe dieabove described. Upon the lower end of thisplunger is slidably mounted a sleeve16,.thi-s 'sleeve vbeing held in place by `a shoulder or likeenlargement 17 at the lower end of the plunger, and, as will be explained hereinafterpisfspring urged toward a position in `which thelowerdend-tof the collarseats uponthis shoulder, as shown in Fig. 1. Gaskets or O-rings 18 of packing material may be provided between the collar and the louter =wallfof1the plungertso tthat arfluid-tight lconnection Iwillbefmade.

The collar 1&6 -is provided with 'an 'outwardly projecting :annularlshoulder-'or stop=member;20, :andtover this shoullder is tpositioned the upper-'open Lend .of abag-or container 21 of exible duid-tight-materlial such as-neoprene, \for example, yalthough:anyfdes'ired material lmay lne-employed. Afwasher122 may'be positionedon thefcollar 16 above the shoulder '20, `so that it *bears upon the lupper -edge of the material of "the bag '121, vthis washer 'being yforced lagainst the materialfof the--bag by a lretaining ring '23 threaded upon 'the' collar `16, as shown at '24. dn this lmanner vthe material t o'f ithe bag xis forced tightly yagainst ythe upper surface-of the AVannular=shoulder'20 to fmafke a 1 fluid-ti ght connection ltherewith.

Acompressionspring25lsurroundszthe plunger-andacts `at its 'lower lend yagainst `the retaining -ring 23 and at its -upper-end'against afstop member '26lsecured in any desired way to the plunger, such -as by the set screw 27. 'The spring will, therefore, tend to hold the collar 16..in 'the position shown in Fig. il, in vwhich gits lowerend abuts the -stop yor'shoulder17 at thelower-:end ofithefplunger. -This will provide for thelmovement of'the bag 21 and collar Withthe plunger unlessand' until rthefrnovement ofthe col- -1ar 16 isfpreventedyand, intha't event, the'plunger will be allowed fto continue 'its movementrelatively to the collar, 4thus inserting the .plungerintofthe'bag The plunger may beprovided with liluid passages '28 and 29fin order-thatfuidmaybelintroducedinto the `bag 21,1the upper endsof these passages opening outwardly lthrough `theplunger by'means of ports 30 yand '31'which 5may be sealed byscrew-threaded plugs 32and 33. Any desired pressure fluid such as oil or water may be introduced -through'one of=these passages,'and the air in the Acontainerwill -befpermitted to exhaustthroughthe other passage so that the container may be iilledtothe desired extent. At its upper end-the -plungermay be secured to any desired actuating means, `such, -for example, as the lram 34 o'f one ofthe usual formsof-mechanical presses.

If desired,an expander-may beusedfto hold the container or bag 21 in extended-position. 4'Such anexpander lis shown at '35, it 3being carried'upon-the lowerend of a stern '36 slidably Areceived in a central bore 37 o'f the plunger 15. A spring 38 in this bore tends -tourge"this Jexpander-to projected position.

In the operation of the device,-the-partsfare-assembled `as shown -in Fig. 1, land -the vcup-shaped workpiece or blank 13 is inserted into'the-opening V1-1 in'the'die'member '10. The ram of the press is then 'brought down, 'causing 'the plunger to descend and the bag 21-'wi11be 'introduced 'into theA workpiece 13, 'as'shown in v'Fig.,3.

At this-time'the collar 20 upon theplunger will engage the upper portion 39 of the die openinggwhich m'aybe slightly enlarged at'this pointtogreceive'it, iso thatthe wall lof the container adjacent nthe `co'llar'will seat ltightly "against thelportion' 39 of the die Vopening andiarrest down- =war`d `movement 'of :the collar. 'The die 'openingwill be `sealed in this manner, and the-punch Awillbepermittedto move relatively'to the die.

Additional movement of the plunger will move it -rela- 'tivelyrto vthe collar 16 and cause its "lower Vend to enter 'the flexible bag '21, as Yshown in -"Fig, '2, compressing 'the -spring 25. This movement Jof :the plungerinto-the bag will force the uid `therein-outwardly, 4thusaexpanding the workpiece and `causing vit 'to conform ito the dieopening -The plunger may'then'be withdrawn, carryingwith it the collar 16Vand Ybag 21 as soon as the spring '25has been 'allowed to expand, thus returning ithe -partstot-hepositionfshown-'in'Fig 1. vAt'this time'the'die 4sections -may be separatedto removethe workj therefrom.

'While 'I" have shown and described apre'ferredtetnbodi- `to `be .limited .to.a1l.of .the `details shown, ,butiscapableof modification and variation .within the spirit of the invention and within the scope of the claims.

What I claim is:

1. A press mechanism comprising a plunger for insertion into a die, a collar slidably mounted on the plunger from which the-plunger may project in both directions,fa pressure fluid .bagof tlexiblernaterial having an open upper end securedtto 'said collar and closed at its lower end, said bag depending from the collar to embrace the 'lower end y'o' fthe plunger and receive the latter therewithin, istop means -on said ,collar 4to :check the movement thereof and permit the plunger to move relatively to the fcollarand the ylowersend of the plunger to descend into the bag and exert pressure on the iluid therein, actuating means connected to the plunger above the collar, a die member having an opening to receive the bag when'the plunger :is actuated, fand means :on the die membertoengagethe stop means ontsa'itl collar to limit movement of the latterand :permit Athe plunger-:to move relatively fto'the :collar and into fthe oag lin the `die opening.

2. A press mechanism comprising .a plunger vfor finsertionintoa-die, a collar=slidably .mounted onitheplunger from :which lthe plunger `may -project in lboth directions, apressureuid bag offex'iblematerial vhaving fan open upper end r`secured ftotsaid collar and closed at its lower endfsaid `bag 'depending ifrom fthe collar'fto embrace'the lower end of the plunger and receive the latter therewithin, stop `means on said collar to 'check the fmovement thereof and permit the l'plunger ftofmove relatively tothe collar'and thelower end of the plunger to descend into the'bag :andexertpressure on'ttheluid therein, actuating rmeans connected to the plunger fabove-the collar, Aa die member having :an -opening :to -treceivefthe 'bag when the :plunger is '-aotuated, and =means lonthe die member to engage the'stop means on saidcollar'fto limit movement of the llatter'fand'permit the plunger 'to move-relatively to the collar and y'into the bag in 'the -die opening, lsaid stop means on Vthe collar comprising a 'laterally projecting'stop member-'to'contact-the dieand close the mouth of the die opening.

3. A press mechanism Jcomprising -`a Lplunger jfor insertion into Ia die, a collar slidably mounted on the plunger 'from which the plunger 1may project in both 'directions, a pressurefluidfbag o'f 'exible material 'having 4an open'upperend secured-torsaid collar and'closed at its'lowerend, said'bag depending fromfthecollar to embrace the lowerfendfofthe plunger'and receive theilatter therewithinystoptmeanson'saidrcollar-to check the movement thereof 'and'perm'it'the plunger to'move relatively to the collar-andthellowerendfof the plungerjto-'descend linto the'bag-and'exert pressure onrthe uid thereinyactuating-means connected to theplunger above `the collar,

-a diemember'having anopening ,to'receive thebag vwhen Athe plunger is actuated, 'means 'on-the die member to engage the stop-means lonesaid collar to limit `movement of the latter and permitthe plunger to move relativelyv'to 'the collar-and intothe'bag-in 'the die opening, retaining means on -`the Aplunger to lretain the collar at the lower portionthereo'fwith the bag projecting from the'end of vtheplunger,4 and means vurging vsaid collar downwardly 'against said fretainingmeans.

"References Cited fin the vtile of this `patent AUNITEDSTATES PATENTS 464,736 'Stapley Dec. "8, 1891 7311,367 IHuber June'16, 1903 v2,001,760 "Barker 'fM-ay T21, 1193.5

2,298,132 "Johnson t :'Oct. f6, 12942 FQREIGN I BATENIS 

